从受砷污染的管井水和土壤来源中分离出的嗜砷阿氏无色杆菌菌株具有相似的基因组潜力。

Arsenotrophic Achromobacter aegrifaciens strains isolated from arsenic contaminated tubewell water and soil sources shared similar genomic potentials.

作者信息

Hoque M Nazmul, Mannan Ayman Bin Abdul, Hossian Anamica, Faisal Golam Mahbub, Hossain M Anwar, Sultana Munawar

机构信息

Department of Microbiology, University of Dhaka, Dhaka, 1000, Bangladesh.

Molecular Biology and Bioinformatics Laboratory, Department of Gynecology, Obstetrics and Reproductive Health, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, 1706, Bangladesh.

出版信息

BMC Microbiol. 2024 Dec 4;24(1):518. doi: 10.1186/s12866-024-03676-9.

DOI:10.1186/s12866-024-03676-9

PMID:39627700

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11616139/

Abstract

BACKGROUND

Arsenic (As), found in diverse ecosystems, poses major public health risks in various parts of the world. Arsenotrophic bacteria in contaminated environments help reduce toxicity by converting arsenite (AsIII) to less harmful arsenate (AsV). We assumed that Achromobacter aegrifaciens strains from As-contaminated tubewell water and soil would share similar genomic characteristics associated with arsenic detoxification and bioremediation. To investigate this, we employed both culture-dependent and culture-independent viz. whole genome sequencing (WGS) methods to thoroughly elucidate the phenotypic and genotypic features of two A. aegrifaciens strains isolated from As-contaminated tubewell water (BAW48) and soil (BAS32) samples collected in the Bogura district of Bangladesh.

RESULTS

Both BAW48 and BAS32 isolates demonstrated As(III) oxidation in the KMNO4 test, which was corroborated by molecular analysis confirming the presence of aioA and arsB genes in both strains. These strains were found to be phylogenetically related to many strains of Achromobacter spp., isolated from biological inorganic reactors, environmental soils, sediments and human clinical samples across diverse geographical regions. Moreover, both strains possessed distinct heavy metal resistance genes conferring resistance to Co, Zn, Cu, Cd, Hg, As, and Cr. Three As gene clusters such as As(III) oxidizing aioBA, As(III) reducing arsRCDAB and the MMA(III) oxidizing ars resistance gene (arsHCsO) cluster were predicted in both genomes of A. aegrifaciens. Further genomic analyses revealed similar profiles in both strains, with mobile genetic elements, antimicrobials and heavy metal resistance genes, virulence genes, and metabolic features. Pangenome and synteny analysis showed that the two genomes are evolutionary distinct from other strains, but closely related to one another.

CONCLUSION

The genomic data confirmed that A. aegrifaciens strains can oxidize As(III) and detoxify heavy metals like As, suggesting their potential for As detoxification and bioremediation. These findings align with our assumption and provide a basis for developing sustainable solutions for bioremediation efforts in As-contaminated environments.

摘要

背景

砷（As）存在于多种生态系统中，在世界不同地区构成重大公共卫生风险。受污染环境中的砷营养细菌通过将亚砷酸盐（AsIII）转化为危害较小的砷酸盐（AsV）来帮助降低毒性。我们假设，从受砷污染的管井水和土壤中分离出的食酸无色杆菌菌株具有与砷解毒和生物修复相关的相似基因组特征。为了对此进行研究，我们采用了依赖培养和不依赖培养的方法，即全基因组测序（WGS）方法，以全面阐明从孟加拉国博古拉地区采集的受砷污染的管井水（BAW48）和土壤（BAS32）样本中分离出的两株食酸无色杆菌菌株的表型和基因型特征。

结果

在高锰酸钾试验中，BAW48和BAS32分离株均表现出As（III）氧化作用，分子分析证实两株菌株中均存在aioA和arsB基因，从而证实了这一结果。发现这些菌株在系统发育上与从不同地理区域的生物无机反应器、环境土壤、沉积物和人类临床样本中分离出的许多食酸无色杆菌菌株相关。此外，两株菌株都拥有独特的重金属抗性基因，对钴、锌、铜、镉、汞、砷和铬具有抗性。在食酸无色杆菌的两个基因组中都预测到了三个砷基因簇，如As（III）氧化的aioBA、As（III）还原的arsRCDAB和甲基砷（III）氧化的抗砷基因（arsHCsO）簇。进一步的基因组分析显示，两株菌株具有相似的特征，包括移动遗传元件、抗菌和重金属抗性基因、毒力基因以及代谢特征。泛基因组和共线性分析表明，这两个基因组在进化上与其他菌株不同，但彼此密切相关。